The Cantor Art Museum at Stanford University is worth an hour or two if you visit campus in Palo Alto, California. In the midst of much construction you can find hourly parking nearby and visit the permanent collection and the special exhibits for free.
There a large number of special exhibits. We saw the exhibit, 500 Years of Italian Master Drawings from the Princeton University Art Museum. I was hoping to see the special exhibit of sculptor Robert Arneson but it opened shortly after our visit.